fix(focus-monitor): allow native focus options to be passed through focusVia (#11962)

Author: crisbeto

src/cdk/a11y/focus-monitor/focus-monitor.spec.ts

@@ -212,6 +212,19 @@ describe('FocusMonitor', () => {
 
     expect(buttonElement.classList.length).toBe(0, 'button should not have any focus classes');
   }));
+
+  it('should pass focus options to the native focus method', fakeAsync(() => {
+    spyOn(buttonElement, 'focus');
+
+    focusMonitor.focusVia(buttonElement, 'program', {preventScroll: true});
+    fixture.detectChanges();
+    tick();
+
+    expect(buttonElement.focus).toHaveBeenCalledWith(jasmine.objectContaining({
+      preventScroll: true
+    }));
+  }));
+
 });
 
 

src/cdk/a11y/focus-monitor/focus-monitor.ts

@@ -29,6 +29,16 @@ export const TOUCH_BUFFER_MS = 650;
 export type FocusOrigin = 'touch' | 'mouse' | 'keyboard' | 'program' | null;
 
 
+/**
+ * Corresponds to the options that can be passed to the native `focus` event.
+ * via https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/focus
+ */
+export interface FocusOptions {
+  /** Whether the browser should scroll to the element when it is focused. */
+  preventScroll?: boolean;
+}
+
+
 type MonitoredElementInfo = {
   unlisten: Function,
   checkChildren: boolean,
@@ -135,15 +145,17 @@ export class FocusMonitor implements OnDestroy {
 
   /**
    * Focuses the element via the specified focus origin.
-   * @param element The element to focus.
-   * @param origin The focus origin.
+   * @param element Element to focus.
+   * @param origin Focus origin.
+   * @param focusOption Options that can be used to configure the focus behavior.
    */
-  focusVia(element: HTMLElement, origin: FocusOrigin): void {
+  focusVia(element: HTMLElement, origin: FocusOrigin, options?: FocusOptions): void {
     this._setOriginForCurrentEventQueue(origin);
 
     // `focus` isn't available on the server
     if (typeof element.focus === 'function') {
-      element.focus();
+      // Cast the element to `any`, because the TS typings don't have the `options` parameter yet.
+      (element as any).focus(options);
     }
   }